import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        int n = input.nextInt();
        int i;
        for(i=2;i<=Math.sqrt(n);i++) {
            if (n % i == 0) {
                System.out.println(n + "不是素数");
                break;
            }
        }
           if(i>Math.sqrt(n)){
               System.out.println(n+"是素数");
           }

    }
}
